Hydrophylium or Hydrophyllium: How To spell?
The word Hydrophylium is misspelled against Hydrophyllium, a noun meaning "One of the flat, leaflike, protective zooids, covering other zooids of certain Siphonophora."
Hydrophyllium has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings hydrophy & ium which should not be misspelled with single 'L'
Wrong Spelling:  hydrophy-l-ium  Correct Spelling:  hydrophy-ll-ium 
Check more misspelled words of Hydrophyllium to spell it correct.